When designing microwave circuits, waveguides are often used due to their low loss. It is often preferable to excite a rectangular waveguide in two polarizations, normally two orthogonal polarizations. Today, this is achieved by using two probes that penetrate the waveguide from two orthogonal directions, where the probes in turn may be connected to suitable connectors on the outside of the waveguide. These arrangements use a lot of components, and are thus very costly.
A typical application for a dual polarized waveguide is within an active electronically scanned array antenna (AESA). Such an antenna comprises a large number of radiating antenna elements, and thus the dual polarized feeding arrangements of today become very expensive, since there are many free-standing components that have to be assembled. Many components that have to be assembled also give rise to problems regarding tolerances which also affect the costs negatively.
There is thus a need for finding a simple and low-cost dual polarized waveguide feed arrangement, which is possible to integrate with existing active T/R-modules (Transmit/Receive).